ECU rule thoughts

[stevel]

Originally posted by Geo:

I still wonder how this plays against my feeling that a Motec is mainly an advantage for ease of adjustment and tuning? In other words, let's say someone wants to optimze their maps (individual or a shop). They could spend time with a Motec hooked up to their stock harness, tune the hell out of it, and then transfer the same values to remap their factory ECU, yes? Now, if I had a Motec, I'd sure rather have it fit the stock box for convenience.

it's never that easy. "Values" are never the same. On a program with a gui such as motec you have values that might or might not mean something. In a stock ecu if you're truly hacking the values, you're probably modifying hex numbers. And trying to get rpm and load points matched up is a mess and usually is not a good solution. You're better off just remapping the stock ecu, dyno, change values, dyno again, etc.

Originally posted by Geo:


I realize that the resolution of the Motec is greater, but does it really make more hp in the mid-range? And if it goes open loop at WOT, you should be able to get the same hp output from a remapped factory ECU shouldn't you?

motec is used for a reason, and besides convenience, it just makes more power. period. If you have 1/3 less points you can use, then what the stock ecu does is interpolate that value based on the values before and after and usually just makes a linear relationship. In actuality that relationship usually isn't linear. What would you rather have? Your stock remapped ecu guessing at values based on others or a precise value that you came to based on tuning?

And if you add VVT to the mix it just makes a greater difference because it's another variable added to the mix. Like someone said, the big dogs are doing it because it works. Just wait til we see variable valve AND cam timing cars making it to IT. I assume something will be clarified by then, but if not the difference will be night and day.

steve




[This message has been edited by stevel (edited November 22, 2004).]

 

[Geo]

Originally posted by stevel:
motec is used for a reason, and besides convenience, it just makes more power.

Ok, how much more? In the end there is one ideal fuel/air mixture.

Originally posted by stevel:
If you have 1/3 less points you can use, then what the stock ecu does is interpolate that value based on the values before and after and usually just makes a linear relationship. In actuality that relationship usually isn't linear. What would you rather have? Your stock remapped ecu guessing at values based on others or a precise value that you came to based on tuning?

OK, a stock Nissan ECU (for example) has a point each 31.x rpm (unless I really blew the math). How much more power can be generated by having an accurate value every 10.x rpm? That's basically what we're talking about.


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

 

[Jeremy Billiel]

I do not mean to bring this up again, but with the new ECU rule in the Jan Fastrack I have a question. Could one modify the ECU case in order to run a cable to datalog?

------------------
Coming Soon: 1995 ITS Acura Integra

 

[Eagle7]

Or even run the cable without modifying the case. I would think not.

------------------
Marty Doane
ITS RX-7 #13
CenDiv WMR

 

[Greg Amy]

Jeremy, the rule is very clear: it must fit within a stock unmodified ECU housing.

Note that the proposed rule also states, "The allowance to modify the ECU in no way permits the addition of wiring, sensors, or piggybacked computers outside of the OEM ECU housing."

So, I say "no".

GA

 

[Quickshoe]

How do they know that your data acquisition system is actually a DA system and not an external computer actually controlling something?

 

[Tak]

Self police ECU's with a simple claim rule. After the race, you can claim your competitor's ECU for the cost of a new one. Anyone want a MOTEC system cheap?

Of course, being the driver of a carburated car, It would be amusing to see a rule allowing any FI on any car. Amusing, but not cheap.

Tak

 

[turboICE]

Originally posted by GregAmy:
Jeremy, the rule is very clear: it must fit within a stock unmodified ECU housing.

It is clearer than that and I wish it was worded like that - if it only had to "fit" within it wouldn't actually have to be within, just fit if it were in.

<font face=\"Verdana, Arial\" size=\"2\">provided that all modifications are done within the original OEM ECU housing.</font>

And what is the definition of the housing? Is it the metal case that encloses it or if the car has a housing that the ecu (including case) resides in could it be there? If the housing were considered the body cavity where the ECU is I could put an AEM in there with the OEM harnesses no problem.

[This message has been edited by turboICE (edited December 15, 2004).]

[This message has been edited by turboICE (edited December 15, 2004).]

 

[Knestis]

I don't do this very often, but...

K

 

[Greg Amy]

Yeah, me too. I'm just *not* in the mood to fight that battle...

 

[stevel]

Originally posted by Geo:
OK, a stock Nissan ECU (for example) has a point each 31.x rpm (unless I really blew the math). How much more power can be generated by having an accurate value every 10.x rpm? That's basically what we're talking about.

well, not every ecu has a point each 31.x rpm. That's my point. Some are every 300 rpm or much more than that. That's where the advantage lies.

Originally posted by Geo:
Ok, how much more? In the end there is one ideal fuel/air mixture.

now that's a loaded question if i ever heard one. I don't necessarily agree that one a/f mixture is the right one for the entire powerband. Some motors respond to being rich in the bottom end and lean in the top end, vice versa, or rich in the middle. So, I disagree with that statement. Also, the a/f mixture that makes the most power may not be the ideal choice as far as reliability is concerned. So, it's never that easy.

s

 

[Geo]

Originally posted by stevel:
now that's a loaded question if i ever heard one. I don't necessarily agree that one a/f mixture is the right one for the entire powerband. Some motors respond to being rich in the bottom end and lean in the top end, vice versa, or rich in the middle. So, I disagree with that statement. Also, the a/f mixture that makes the most power may not be the ideal choice as far as reliability is concerned. So, it's never that easy.

I agree. But if WOT at 5000 rpm works best at X mixture, if you get that mixture built into your map, who cares if the map is in a MoTeC or a remaped factory ECU? See what I mean. I do get your point about some ECUs don't have that much resolution.

BTW, folks should be careful reading into my arguments in this discussion. It's a matter of fact finding and cutting through the BS. If I'm all wet, I'd like to know, but I'd like to know why because then I can understand it better. I DO think there are people out there who think a MoTeC can make mysterious power, but when you get right down to it, there are limited parameters to a map.

That said, I have a bit better understanding of one way a MoTeC can increase power. But now we are down to how much more? I don't believe for a second it's even 10 hp, assuming you can remap your factory ECU.

In the end, this is not a simple issue and there are a lot emotions in this issue, largely (I think) because of the dollars involved.

Now, to throw another monkey wrench into this (hey, I'm a bit of a monkey, so why not?)....

Greg mentioned one time about the Unichip. Is it not possible to install a Unichip inside the ECU box and interrupt the signal inside the box? If so, there is still opportunity for using a Unichip.

I mention this because once I said something about merely requiring the stock ECU board be in place and folks told me they could still place a MoTeC in the box with the stock board in place.



------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

 

[turboICE]

Originally posted by Knestis:
I don't do this very often, but...

K

I agree, I roll my eyes at most of these threads the rules are not very hard to interpret by reasonable folks - was just illustrating how silly interpreting could get. :shrugs:

 

[Bill Miller]

<font face=\"Verdana, Arial\" size=\"2\">Originally posted by Geo: I don't believe for a second it's even 10 hp, assuming you can remap your factory ECU.</font>

George,

Increase in peak hp is not the issue, it's the increase in the area under the curve. We've had this discussion before. It's entirely possible to not increase peak hp, but to signifcantly increase the area under the curve, which translates to a broader power band.

------------------
MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

 

[Geo]

Originally posted by Bill Miller:
George,

Increase in peak hp is not the issue, it's the increase in the area under the curve. We've had this discussion before. It's entirely possible to not increase peak hp, but to signifcantly increase the area under the curve, which translates to a broader power band.

I understand area under the curve quite well. But the question still remains, if mixture X at Y rpm is ideal, what's the difference if you're using a remapped factory ECU to do it or a MoTeC?

I also realize the MoTeC has finer resolution on its maps. But the question remains, how much difference in hp is there going to be?


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

 

[Andy Bettencourt]

Geo,

The difference will be nothing. A map is a map. But HOW do you get the data to burn that static chip if you don't have a fully programmable unit to do the testing?

Dyno pull, examine results, tweak. Repeat hundreds of times in order to get optimum.

Now if you were an entrapanuer, you could develop using MOTEC and sell a remmapped plug-in as a product but then you have other issues:

- everyone must be using the same exact 'power package' as you. ie: filter, exhaust, internal engine configuration, fuel pressure, plugs, etc... Otherwise the data doesn't 'fit'. How ya gonna insure this?
- it doesn't take into account the aging of the engine. A remapped ECU will only be optimal for a finite period of time while the MOTEC unit can be tested and tweaked at the end of every season or x amount of hours.

It's small potatos but that is what these things are meant to smooth out and optimize.

Andy

------------------
Andy Bettencourt
New England Region, R188967
ITA project SM
www.flatout-motorsports.com

 

[x-ring]

Originally posted by Geo:
Now, to throw another monkey wrench into this (hey, I'm a bit of a monkey, so why not?)....

So would that make you,,, CURIOUS GEORGE?

Sorry, I just couldn't let that one pass.

------------------
Ty Till
#16 ITS
Rocky Mountain Division

 

[chipbond]

George,

Matt Green's very informative posts above include this:

"Also, BLM's affect long-term fuel trim numbers, which affect WOT maps (these cannot be locked in most ECU setups without hard-editing the hex code)."

Though I'm not certain what is involved in "hard editing", it certainly sounds beyond the ability and budget of most club racers. Even more so when, to do so will require a combined dyno/"hard editing" session.

Also keep in mind that the stock system I am most familiar with (maybe all?), looses all "learned" data whenever +12V is lost...like battery change, winter storage, etc....

I think the answer to your question is "yes" a stock ECU could, perhaps, deliver the same level of performance as an aftermarket, but the effort to get it there...AND TO KEEP IT THERE....would be a budget breaker for even the best funded efforts.

Contrast that to a one-time investment of the $1500 I describe above.

Chip Bond
#37 EP Caterham
#227042

 

[stevel]

Originally posted by Andy Bettencourt:
Geo,

The difference will be nothing. A map is a map. But HOW do you get the data to burn that static chip if you don't have a fully programmable unit to do the testing?

That's why I like pre 2001 hondas. Don't need a fully programmable unit. An EEPROM emulator, gui map editor (which are free or can be aftermarket), a wideband, serial port soldered to the stock "chipped" ecu board for datalogging and some dyno time and I can pretty much get out of it what a motec can. It's nice when there's so many people out there reverse engineering the ecu for you.

s



[This message has been edited by stevel (edited December 17, 2004).]

 

[Geo]

Originally posted by chipbond:
I think the answer to your question is "yes" a stock ECU could, perhaps, deliver the same level of performance as an aftermarket, but the effort to get it there...AND TO KEEP IT THERE....would be a budget breaker for even the best funded efforts.

Contrast that to a one-time investment of the $1500 I describe above.

Chip, I have not forgotten Matt's explanation. I'm not trying to push a single point here. I actually do believe a MoTeC is an advantage, not the least of which is ease (if you call it easy) of tuning.

Looking at this from the position of a rule maker (or advisor in this case), you (or at least I have to ask, "What happens if we tried to change the rule?" (which is not in current discussion AFAIK). As Andy suggested, someone could do tuning with a MoTeC and then burn maps that match (other than resolution) in a replaceable chip. What happens if someone rigs a Unichip inside an ECU box?

I just think that A) this is not as simple as we'd like to think, and the MoTeC fear is (IMHO) a bit over blown. It's not going to make a mid-packer a sudden winner. It might make someone knocking on the door a winner.

That's what's going through my mind, however empty, warped, and twisted as it may be.

------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[This message has been edited by Geo (edited December 17, 2004).]